allow object type in dict.get and dict.pop by randolf-scholz · Pull Request #15471 · python/typeshed

randolf-scholz · 2026-02-28T16:59:36Z

Fixes #15271
Supersedes: #15297

This PR only changes dict, but not MutableMapping, and changes the signature of dict.get and dict.pop to allow object as key arguments. (allows these methods to work with partially overlapping types)

github-actions · 2026-03-02T21:06:56Z

Diff from mypy_primer, showing the effect of this PR on open source code:

mongo-python-driver (https://github.com/mongodb/mongo-python-driver)
+ bson/son.py:126: error: Signature of "pop" incompatible with supertype "builtins.dict"  [override]
+ bson/son.py:126: note:      Superclass:
+ bson/son.py:126: note:          @overload
+ bson/son.py:126: note:          def pop(self, object, /) -> _Value
+ bson/son.py:126: note:          @overload
+ bson/son.py:126: note:          def pop(self, object, _Value, /) -> _Value
+ bson/son.py:126: note:          @overload
+ bson/son.py:126: note:          def [_T] pop(self, object, _T, /) -> _Value | _T
+ bson/son.py:126: note:      Subclass:
+ bson/son.py:126: note:          def [_T] pop(self, key: _Key, *args: _Value | _T) -> _Value | _T

setuptools (https://github.com/pypa/setuptools)
+ setuptools/_static.py:170: error: Unused "type: ignore" comment  [unused-ignore]

pylox (https://github.com/sco1/pylox)
+ pylox/containers/array.py:83: note:     def pop(self, object, /) -> Any
- pylox/containers/array.py:83: note:     def pop(self, Any, /) -> Any
+ pylox/containers/array.py:83: note:     def pop(self, object, Any, /) -> Any
- pylox/containers/array.py:83: note:     def pop(self, Any, Any, /) -> Any
- pylox/containers/array.py:83: note:     def [_T] pop(self, Any, _T, /) -> Any | _T
+ pylox/containers/array.py:83: note:     def [_T] pop(self, object, _T, /) -> Any | _T

rotki (https://github.com/rotki/rotki)
+ rotkehlchen/tasks/events.py:813: error: Unused "type: ignore" comment  [unused-ignore]
+ rotkehlchen/chain/aggregator.py:732: error: Unused "type: ignore" comment  [unused-ignore]

django-stubs (https://github.com/typeddjango/django-stubs)
+ django-stubs/utils/datastructures.pyi:65: error: Signature of "get" incompatible with supertype "builtins.dict"  [override]
+ django-stubs/utils/datastructures.pyi:65: note:      Superclass:
+ django-stubs/utils/datastructures.pyi:65: note:          @overload
+ django-stubs/utils/datastructures.pyi:65: note:          def get(self, object, None = ..., /) -> _V | None
+ django-stubs/utils/datastructures.pyi:65: note:          @overload
+ django-stubs/utils/datastructures.pyi:65: note:          def get(self, object, _V, /) -> _V
+ django-stubs/utils/datastructures.pyi:65: note:          @overload
+ django-stubs/utils/datastructures.pyi:65: note:          def [_T] get(self, object, _T, /) -> _V | _T
+ django-stubs/utils/datastructures.pyi:65: note:      Subclass:
+ django-stubs/utils/datastructures.pyi:65: note:          @overload
+ django-stubs/utils/datastructures.pyi:65: note:          def get(self, key: _K, default: None = ...) -> _V | None
+ django-stubs/utils/datastructures.pyi:65: note:          @overload
+ django-stubs/utils/datastructures.pyi:65: note:          def get(self, key: _K, default: _V) -> _V
+ django-stubs/utils/datastructures.pyi:65: note:          @overload
+ django-stubs/utils/datastructures.pyi:65: note:          def [_Z] get(self, key: _K, default: _Z) -> _V | _Z
+ django-stubs/contrib/sessions/backends/base.pyi:31: error: Signature of "pop" incompatible with supertype "builtins.dict"  [override]
+ django-stubs/contrib/sessions/backends/base.pyi:31: note:      Superclass:
+ django-stubs/contrib/sessions/backends/base.pyi:31: note:          @overload
+ django-stubs/contrib/sessions/backends/base.pyi:31: note:          def pop(self, object, /) -> Any
+ django-stubs/contrib/sessions/backends/base.pyi:31: note:          @overload
+ django-stubs/contrib/sessions/backends/base.pyi:31: note:          def pop(self, object, Any, /) -> Any
+ django-stubs/contrib/sessions/backends/base.pyi:31: note:          @overload
+ django-stubs/contrib/sessions/backends/base.pyi:31: note:          def [_T] pop(self, object, _T, /) -> Any | _T
+ django-stubs/contrib/sessions/backends/base.pyi:31: note:      Subclass:
+ django-stubs/contrib/sessions/backends/base.pyi:31: note:          @overload
+ django-stubs/contrib/sessions/backends/base.pyi:31: note:          def pop(self, key: str) -> Any
+ django-stubs/contrib/sessions/backends/base.pyi:31: note:          @overload
+ django-stubs/contrib/sessions/backends/base.pyi:31: note:          def pop(self, key: str, default: Any) -> Any
+ django-stubs/http/request.pyi:202: error: Signature of "pop" incompatible with supertype "builtins.dict"  [override]
+ django-stubs/http/request.pyi:202: note:      Superclass:
+ django-stubs/http/request.pyi:202: note:          @overload
+ django-stubs/http/request.pyi:202: note:          def pop(self, object, /) -> str
+ django-stubs/http/request.pyi:202: note:          @overload
+ django-stubs/http/request.pyi:202: note:          def pop(self, object, str, /) -> str
+ django-stubs/http/request.pyi:202: note:          @overload
+ django-stubs/http/request.pyi:202: note:          def [_T] pop(self, object, _T, /) -> str | _T
+ django-stubs/http/request.pyi:202: note:      Subclass:
+ django-stubs/http/request.pyi:202: note:          @overload
+ django-stubs/http/request.pyi:202: note:          def pop(self, str | bytes, /) -> Never
+ django-stubs/http/request.pyi:202: note:          @overload
+ django-stubs/http/request.pyi:202: note:          def [_Z] pop(self, str | bytes, str | _Z = ..., /) -> Never

beartype (https://github.com/beartype/beartype)
+ beartype/_check/convert/_reduce/redmain.py:606: error: Unused "type: ignore" comment  [unused-ignore]
+ beartype/_check/convert/_reduce/redmain.py:697: error: Unused "type: ignore" comment  [unused-ignore]
+ beartype/_check/code/_pep/pep484585/codepep484585container.py:99: error: Unused "type: ignore" comment  [unused-ignore]
+ beartype/door/_cls/pep/pep484585/doorpep484585subscripted.py:50: error: Unused "type: ignore" comment  [unused-ignore]
+ beartype/door/_cls/util/doorclsmap.py:91: error: Unused "type: ignore" comment  [unused-ignore]

pandas (https://github.com/pandas-dev/pandas)
+ pandas/core/arrays/arrow/array.py:3400: error: Unused "type: ignore" comment  [unused-ignore]

starlette (https://github.com/encode/starlette)
+ starlette/middleware/sessions.py:114: error: Signature of "pop" incompatible with supertype "builtins.dict"  [override]
+ starlette/middleware/sessions.py:114: note:      Superclass:
+ starlette/middleware/sessions.py:114: note:          @overload
+ starlette/middleware/sessions.py:114: note:          def pop(self, object, /) -> Any
+ starlette/middleware/sessions.py:114: note:          @overload
+ starlette/middleware/sessions.py:114: note:          def pop(self, object, Any, /) -> Any
+ starlette/middleware/sessions.py:114: note:          @overload
+ starlette/middleware/sessions.py:114: note:          def [_T] pop(self, object, _T, /) -> Any | _T
+ starlette/middleware/sessions.py:114: note:      Subclass:
+ starlette/middleware/sessions.py:114: note:          def pop(self, key: str, *args: Any) -> Any

scrapy (https://github.com/scrapy/scrapy)
+ scrapy/utils/datatypes.py:82: error: Signature of "get" incompatible with supertype "builtins.dict"  [override]
+ scrapy/utils/datatypes.py:82: note:      Superclass:
+ scrapy/utils/datatypes.py:82: note:          @overload
+ scrapy/utils/datatypes.py:82: note:          def get(self, object, None = ..., /) -> Any | None
+ scrapy/utils/datatypes.py:82: note:          @overload
+ scrapy/utils/datatypes.py:82: note:          def get(self, object, Any, /) -> Any
+ scrapy/utils/datatypes.py:82: note:          @overload
+ scrapy/utils/datatypes.py:82: note:          def [_T] get(self, object, _T, /) -> Any | _T
+ scrapy/utils/datatypes.py:82: note:      Subclass:
+ scrapy/utils/datatypes.py:82: note:          def [AnyStr: (str, bytes)] get(self, key: AnyStr, def_val: Any = ...) -> Any
+ scrapy/utils/datatypes.py:98: error: Signature of "pop" incompatible with supertype "builtins.dict"  [override]
+ scrapy/utils/datatypes.py:98: note:      Superclass:
+ scrapy/utils/datatypes.py:98: note:          @overload
+ scrapy/utils/datatypes.py:98: note:          def pop(self, object, /) -> Any
+ scrapy/utils/datatypes.py:98: note:          @overload
+ scrapy/utils/datatypes.py:98: note:          def pop(self, object, Any, /) -> Any
+ scrapy/utils/datatypes.py:98: note:          @overload
+ scrapy/utils/datatypes.py:98: note:          def [_T] pop(self, object, _T, /) -> Any | _T
+ scrapy/utils/datatypes.py:98: note:      Subclass:
+ scrapy/utils/datatypes.py:98: note:          def [AnyStr: (str, bytes)] pop(self, key: AnyStr, *args: Any) -> Any
+ scrapy/http/headers.py:76: error: Signature of "get" incompatible with supertype "builtins.dict"  [override]
+ scrapy/http/headers.py:76: note:      Superclass:
+ scrapy/http/headers.py:76: note:          @overload
+ scrapy/http/headers.py:76: note:          def get(self, object, None = ..., /) -> Any | None
+ scrapy/http/headers.py:76: note:          @overload
+ scrapy/http/headers.py:76: note:          def get(self, object, Any, /) -> Any
+ scrapy/http/headers.py:76: note:          @overload
+ scrapy/http/headers.py:76: note:          def [_T] get(self, object, _T, /) -> Any | _T
+ scrapy/http/headers.py:76: note:      Subclass:
+ scrapy/http/headers.py:76: note:          def [AnyStr: (str, bytes)] get(self, key: AnyStr, def_val: Any = ...) -> bytes | None

pylint (https://github.com/pycqa/pylint)
+ pylint/config/arguments_provider.py:54: error: Incompatible types in "yield" (actual type "tuple[None, list[tuple[str, dict[str, str | bool | int | Pattern[str] | Iterable[str | int | Pattern[str]] | type[_CallbackAction] | Callable[[Any], Any] | Callable[[Any, Any, Any, Any], Any] | None], Any]]]", expected type "tuple[str, list[tuple[str, dict[str, str | bool | int | Pattern[str] | Iterable[str | int | Pattern[str]] | type[_CallbackAction] | Callable[[Any], Any] | Callable[[Any, Any, Any, Any], Any] | None], Any]]] | tuple[None, dict[str, list[tuple[str, dict[str, str | bool | int | Pattern[str] | Iterable[str | int | Pattern[str]] | type[_CallbackAction] | Callable[[Any], Any] | Callable[[Any, Any, Any, Any], Any] | None], Any]]]]")  [misc]
+ pylint/config/arguments_provider.py:54: note: Error code "misc" not covered by "type: ignore" comment
+ pylint/config/arguments_provider.py:54: error: Unused "type: ignore" comment  [unused-ignore]

jax (https://github.com/google/jax)
+ jax/_src/interpreters/partial_eval.py:1358: error: Unused "type: ignore" comment  [unused-ignore]
+ jax/_src/interpreters/partial_eval.py:1365: error: Unused "type: ignore" comment  [unused-ignore]

discord.py (https://github.com/Rapptz/discord.py)
+ discord/state.py:372: error: Unused "type: ignore" comment  [unused-ignore]
+ discord/state.py:437: error: Unused "type: ignore" comment  [unused-ignore]
+ discord/state.py:474: error: Unused "type: ignore" comment  [unused-ignore]
+ discord/state.py:478: error: Unused "type: ignore" comment  [unused-ignore]
+ discord/state.py:497: error: Unused "type: ignore" comment  [unused-ignore]
- discord/ui/view.py:961: error: No overload variant of "pop" of "dict" matches argument types "tuple[int, str]", "None"  [call-overload]
- discord/ui/view.py:961: note: Possible overload variants:
- discord/ui/view.py:961: note:     def pop(self, Pattern[str], /) -> type[DynamicItem[Item[Any]]]
- discord/ui/view.py:961: note:     def pop(self, Pattern[str], type[DynamicItem[Item[Any]]], /) -> type[DynamicItem[Item[Any]]]
- discord/ui/view.py:961: note:     def [_T] pop(self, Pattern[str], _T, /) -> type[DynamicItem[Item[Any]]] | _T
+ discord/ui/view.py:986: error: Unused "type: ignore" comment  [unused-ignore]
- discord/ui/view.py:981: error: No overload variant of "pop" of "dict" matches argument types "tuple[int, str]", "None"  [call-overload]
- discord/ui/view.py:981: note: Possible overload variants:
- discord/ui/view.py:981: note:     def pop(self, Pattern[str], /) -> type[DynamicItem[Item[Any]]]
- discord/ui/view.py:981: note:     def pop(self, Pattern[str], type[DynamicItem[Item[Any]]], /) -> type[DynamicItem[Item[Any]]]
- discord/ui/view.py:981: note:     def [_T] pop(self, Pattern[str], _T, /) -> type[DynamicItem[Item[Any]]] | _T

steam.py (https://github.com/Gobot1234/steam.py)
- steam/ext/commands/utils.py:43: note:          def get(self, str, None = ..., /) -> _VT | None
+ steam/ext/commands/utils.py:43: note:          def get(self, object, None = ..., /) -> _VT | None
- steam/ext/commands/utils.py:43: note:          def get(self, str, _VT, /) -> _VT
+ steam/ext/commands/utils.py:43: note:          def get(self, object, _VT, /) -> _VT
- steam/ext/commands/utils.py:43: note:          def [_T] get(self, str, _T, /) -> _VT | _T
+ steam/ext/commands/utils.py:43: note:          def [_T] get(self, object, _T, /) -> _VT | _T
- steam/ext/commands/utils.py:52: note:          def pop(self, str, /) -> _VT
+ steam/ext/commands/utils.py:52: note:          def pop(self, object, /) -> _VT
- steam/ext/commands/utils.py:52: note:          def pop(self, str, _VT, /) -> _VT
+ steam/ext/commands/utils.py:52: note:          def pop(self, object, _VT, /) -> _VT
- steam/ext/commands/utils.py:52: note:          def [_T] pop(self, str, _T, /) -> _VT | _T
+ steam/ext/commands/utils.py:52: note:          def [_T] pop(self, object, _T, /) -> _VT | _T
+ steam/ext/commands/bot.py:537: error: Unused "type: ignore" comment  [unused-ignore]

altair (https://github.com/vega/altair)
+ altair/utils/html.py:394: error: Unused "type: ignore" comment  [unused-ignore]
+ altair/utils/html.py:399: error: Item "str" of "Literal['standard', 'universal', 'inline', 'olli'] | Template" has no attribute "render"  [union-attr]

werkzeug (https://github.com/pallets/werkzeug)
+ src/werkzeug/datastructures/mixins.py:265: error: Signature of "pop" incompatible with supertype "builtins.dict"  [override]
+ src/werkzeug/datastructures/mixins.py:265: note:      Superclass:
+ src/werkzeug/datastructures/mixins.py:265: note:          @overload
+ src/werkzeug/datastructures/mixins.py:265: note:          def pop(self, object, /) -> V
+ src/werkzeug/datastructures/mixins.py:265: note:          @overload
+ src/werkzeug/datastructures/mixins.py:265: note:          def pop(self, object, V, /) -> V
+ src/werkzeug/datastructures/mixins.py:265: note:          @overload
+ src/werkzeug/datastructures/mixins.py:265: note:          def [_T] pop(self, object, _T, /) -> V | _T
+ src/werkzeug/datastructures/mixins.py:265: note:      Subclass:
+ src/werkzeug/datastructures/mixins.py:265: note:          @overload
+ src/werkzeug/datastructures/mixins.py:265: note:          def pop(self, key: K) -> V
+ src/werkzeug/datastructures/mixins.py:265: note:          @overload
+ src/werkzeug/datastructures/mixins.py:265: note:          def pop(self, key: K, default: V) -> V
+ src/werkzeug/datastructures/mixins.py:265: note:          @overload
+ src/werkzeug/datastructures/mixins.py:265: note:          def [T] pop(self, key: K, default: T) -> T
+ src/werkzeug/exceptions.py:94: error: Unused "type: ignore" comment  [unused-ignore]
+ src/werkzeug/datastructures/structures.py:469: error: Signature of "pop" incompatible with supertype "builtins.dict"  [override]
+ src/werkzeug/datastructures/structures.py:469: note:      Superclass:
+ src/werkzeug/datastructures/structures.py:469: note:          @overload
+ src/werkzeug/datastructures/structures.py:469: note:          def pop(self, object, /) -> V
+ src/werkzeug/datastructures/structures.py:469: note:          @overload
+ src/werkzeug/datastructures/structures.py:469: note:          def pop(self, object, V, /) -> V
+ src/werkzeug/datastructures/structures.py:469: note:          @overload
+ src/werkzeug/datastructures/structures.py:469: note:          def [_T] pop(self, object, _T, /) -> V | _T
+ src/werkzeug/datastructures/structures.py:469: note:      Subclass:
+ src/werkzeug/datastructures/structures.py:469: note:          @overload
+ src/werkzeug/datastructures/structures.py:469: note:          def pop(self, key: K) -> V
+ src/werkzeug/datastructures/structures.py:469: note:          @overload
+ src/werkzeug/datastructures/structures.py:469: note:          def pop(self, key: K, default: V) -> V
+ src/werkzeug/datastructures/structures.py:469: note:          @overload
+ src/werkzeug/datastructures/structures.py:469: note:          def [T] pop(self, key: K, default: T) -> V | T
+ src/werkzeug/debug/__init__.py:553: error: Unused "type: ignore" comment  [unused-ignore]

operator (https://github.com/canonical/operator)
- ops/_private/harness.py:2649: error: No overload variant of "pop" of "dict" matches argument types "str", "None"  [call-overload]
- ops/_private/harness.py:2649: note: Possible overload variants:
- ops/_private/harness.py:2649: note:     def pop(self, int, /) -> dict[str, Any]
- ops/_private/harness.py:2649: note:     def pop(self, int, dict[str, Any], /) -> dict[str, Any]
- ops/_private/harness.py:2649: note:     def [_T] pop(self, int, _T, /) -> dict[str, Any] | _T

cki-lib (https://gitlab.com/cki-project/cki-lib)
- tests/utils.py:22: error: Argument 1 to "get" of "dict" has incompatible type "int | str"; expected "str"  [arg-type]
- tests/utils.py:22: error: Argument 2 to "get" of "dict" has incompatible type "int | str"; expected "int"  [arg-type]

jinja (https://github.com/pallets/jinja)
+ src/jinja2/compiler.py:1422: error: Unused "type: ignore" comment  [unused-ignore]
+ src/jinja2/environment.py:514: error: Unused "type: ignore" comment  [unused-ignore]

AlexWaygood · 2026-03-08T19:50:14Z

I count 28 errors going away in the ecosystem and 9 errors being added

randolf-scholz · 2026-03-09T09:05:45Z

Well those 9 errors are as expected all override type errors which are unavoidable if we use key: object. (they could be avoided by using key: Any but as we discussed you strongly advise for object in the case of builtins.dict.

Btw. is it really approapriate that typeshed still only uses mypy the reference here? Shouldn't we also consider impact with other type checkers? For instance, with ty I noticed this annoyance which I believe should go away with this PR (though there may be some more specific underlying issue)

def is_config(obj: object):
    if not isinstance(obj, dict):
        return False
    if not isinstance(obj.get("_target_"), str):  # ty: expected Never, found "_target_"
        return False
    return True

https://play.ty.dev/8f5313f7-cf67-4018-bd5f-e935cf9e4741

(astral-sh/ty#2374)

AlexWaygood · 2026-03-09T09:12:32Z

Well those 9 errors are as expected all override type errors which are unavoidable if we use key: object.

Yeah I agree! Sorry, I only got partway through a review last night

AlexWaygood · 2026-03-09T09:15:20Z

Btw. is it really approapriate that typeshed still only uses mypy the reference here? Shouldn't we also consider impact with other type checkers?

We've discussed this in the past (#7642) — we could certainly discuss it again now that there are even more type checkers on the scene. Mypy is still the most popular type checker around, so it will continue to have a lot of weight in our decisions here for a while, but as the author of another type checker I do obviously agree that we should consider other type checkers as well when making decisions in this repo 😄

randolf-scholz added 3 commits February 28, 2026 17:57

allow object type in dict.get and dict.pop

e3aa188

mixed metadata stubtest failure

f513d04

fixed boltons stubtest failure

4dcab82

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fixes stubtest failures

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This was referenced Feb 28, 2026

Allow arbitrary types in dict.pop (3 overloads) #15297

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Several methods on built-in types are too strict. #15271

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Merge branch 'main' into dict_signatures

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allow object type in dict.get and dict.pop#15471

allow object type in dict.get and dict.pop#15471
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